How do I apply for a commercial building permit in unincorporated Ada County?

Submit your commercial building permit application and all plan documents as individual PDF files by email to mechanical@adacounty.id.gov. The Permitting Team will contact you for payment once the application is confirmed complete. Accepted payment: e-check ($3 flat) or credit card (2.4% convenience fee, minimum $2). Source: adacounty.id.gov/developmentservices/permitting-division/applications-forms-templates/

Commercial Building Permit (New Construction / Tenant Improvement) in Unincorporated Ada County, Idaho

Required for all new commercial, industrial, and multi-family buildings (three or more units), tenant improvements, remodels, and change-of-use projects in unincorporated Ada County. Governed by the 2018 International Building Code (IBC) as adopted by Ada County Ordinance #919. Applications submitted digitally by email.

Verified 2026-06-29 · Source

When you need this permit

Required for new commercial/industrial buildings, multi-family structures (3+ units), tenant improvements, and change-of-occupancy projects
Submit complete digital PDF application package (application form + all plan sheets as individual files, not in a zip) by email to mechanical@adacounty.id.gov
Commercial Building Permit application form required
Full plan set drawn to scale and dimensioned; not all items apply to all structures
Post-frame and steel buildings require stamped engineering including foundation design
Structural calculations may be required by the plans examiner during review for non-standard materials or non-prescriptive construction

Required documents

Req
Commercial Building Permit Application (.docx)
Ada County commercial building permit application; available at adacounty.id.gov/developmentservices/permitting-division/applications-forms-templates/
Req
Full Commercial Plan Set
All required drawings per plan examiner direction — site plan, floor plan, structural plans, architectural plans; each submitted as an individual PDF file

Fee schedule

Fee type	Amount	Notes
Building permit fee	Valuation-based per Ada County 2025 Fee Schedule (Resolution 3149, effective November 2025); see Building-Fees.pdf at adacounty.id.gov/developmentservices/permitting-division/fees/	Credit card payments: 2.4% convenience fee (minimum $2); e-checks: $3.00 flat rate.

Review timeline

~10–30 business days

Typical estimate — confirm current times with the Unincorporated Ada County building department

Inspection process

1
Footing / Foundation
Request by 4:30 PM by phone or before midnight by email for next-day scheduling
2
Framing / Structural
After structural framing complete and before wall cover
3
Final
All work complete per approved plans; Certificate of Occupancy issued

Tips

Submit each document as a separate PDF file. Do not merge into a single file or compress into a zip archive — zips take longer to process.
Post-frame and steel buildings always require stamped engineering from an Idaho-licensed design professional, including foundation design.
Electrical work falls under the Idaho Division of Building Safety (DBS), not Ada County Building Division.

Frequently asked questions

How do I apply for a commercial building permit in unincorporated Ada County?: Submit your commercial building permit application and all plan documents as individual PDF files by email to mechanical@adacounty.id.gov. The Permitting Team will contact you for payment once the application is confirmed complete. Accepted payment: e-check ($3 flat) or credit card (2.4% convenience fee, minimum $2). Source: adacounty.id.gov/developmentservices/permitting-division/applications-forms-templates/

Sources & verification

Verified against official sources. Last reviewed 2026-06-29.

Fees, timelines, and adopted codes are researched from each jurisdiction's published records — see how we verify. Requirements change and vary by project, so always confirm the current details with the Unincorporated Ada County building department before you submit. PermitBase is an independent reference and is not affiliated with any government agency.

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